Added theme, reworked UI

lib/app.dart

@@ -4,6 +4,7 @@ import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:tunas/clients/storage/storage_client.dart';
 import 'package:tunas/pages/home/home_page.dart';
 import 'package:tunas/repositories/account/account_repository.dart';
+import 'package:tunas/theme.dart';
 
 class App extends StatefulWidget {
   const App({super.key});
@@ -44,13 +45,9 @@ class _AppViewState extends State<AppView> {
       providers: [RepositoryProvider.value(value: _accountRepository)],
       child: MaterialApp(
         title: 'Tunas',
-        theme: ThemeData(
-          colorScheme: ColorScheme.fromSeed(
-            seedColor: const Color.fromARGB(255, 55, 55, 55),
-            brightness: Brightness.dark
-          ),
-          useMaterial3: true
-        ),
+        theme: ThemeData(useMaterial3: true, colorScheme: lightColorScheme),
+        darkTheme: ThemeData(useMaterial3: true, colorScheme: darkColorScheme),
+        themeMode: ThemeMode.dark,
         initialRoute: '/home',
         routes: {
           '/home':(context) => const HomePage(),